The present invention relates to internal combustion engines. In particular, the present invention relates to an air intake system for an internal combustion engine.
Internal combustion engines operate by creating a controlled combustion of a mixture of fuel and air within a cylinder of the engine. Ultimately the energy produced by this combustion is transmitted to a drive shaft or other means for providing a locomotive force to gear or wheel.
To create this combustion within the cylinder, air must be taken from outside the engine and combined with fuel to create an inflammable gas mixture. A carburetor typically performs this task. The carburetor selectively guides the flow of air and fuel into a main conduit of the carburetor where the air and fuel are mixed into the inflammable gas. This gas mixture is then delivered to a cylinder of the engine for combustion therein.
The air intake system for a carburetor typically has an air filter positioned outside of the main conduit. This air filter removes undesirable particles, such as dirt and oil, from the air as the air is passing from the outside environment into the carburetor. The air filter is encompassed within a housing which covers the air filter and directs the flow of air into and through the air filter. Once the air passes through the air filter, it passes down into a mouth of the carburetor.
The horsepower produced by an engine is limited in part as a function of the air-fuel mixture ratio. One way of increasing the horsepower of the engine is by providing a greater amount of air available for mixing with the fuel. However, the air must be provided to the carburetor without over pressurizing the carburetor float bowl which would impede engine performance. Some known methods of increasing the horsepower of an engine by augmenting the air that enters the carburetor include supercharging and turbocharging.
The amount of air entering the carburetor is typically limited by the fixed configuration of the intake openings in the air filter housing. These openings are sized and positioned to direct an adequate amount of air through the air filter and into the carburetor without over pressurizing the carburetor float bowl. The housings usually do not provide a means for selectively closing the openings or selectively varying the amount of air permitted to flow through the housing (and ultimately the carburetor).